1. Field of the invention
The present invention relates to a patterning apparatus and a patterning method using the same, and more particularly to an apparatus for fabricating a pattern of a continuous structure, which is used in a large-area display, and a method for fabricating a pattern of a continuous structure using the same.
As used herein, the pattern of a continuous structure refers to a pattern of, e.g., barrier ribs of a Plasma display panel (PDP), which are arranged in line in one direction with a uniform cross section.
2. Description of the Related Art
Conventional patterning methods include an electron beam lithography method, an optical lithography method, and an X-ray lithography method.
According to the electron beam lithography method, a photosensitive agent, which reacts to electrons, is applied on the upper surface of a substrate and a predetermined pattern is directly etched using electron beams, without any mask. This method can form a high-resolution pattern of 0.2 μm or less, since the electrons have a short wavelength.
However, it takes a long time to etch a predetermined pattern using the electron beam lithography method. This decreases productivity. In addition, since the depth of a formed pattern is small, the accuracy of overlay and etching is poor. Furthermore, the method uses expensive electron-emission equipment. Consequently, the electron beam lithography method is not suitable for fabricating a pattern for use in a large-area display panel.
According to the optical lithography method, a photosensitive agent is applied on the upper surface of a substrate, a mask is placed thereon, and UV rays are irradiated to fabricate a predetermined pattern. This method can form a vertical or slanted pattern according to the irradiation angle of the UV rays.
However, if the optical lithography method is used, it is difficult to fabricate a vertical pattern with a thickness of a few tens of μm or more, as well as to form a uniformly slanted pattern, due to the diffraction characteristics peculiar to the UV rays. In addition, since the UV rays have dispersion, they cannot be irradiated only on selected portions or form a micro-pattern with a line width of 0.2 μm or less. Accordingly, this method cannot form a highly-integrated pattern.
According to an X-ray lithography method, a photosensitive agent is applied on the upper surface of a substrate and X-rays are irradiated via a mask to fabricate a predetermined pattern. Since the X-rays have a short wavelength, this method can form a micro-structure with a line width of 0.1 μm or less.
However, when a substrate 1 and a mask 2 are kept parallel to each other and X-rays are irradiated with a slant to form a pattern 1a of a slanted structure, as shown in FIG. 1, a problem occurs as follows:
If the mask 2 is positioned with a slant relative to the X-rays, there is a difference in the traveling distance L1, L2 of the X-rays to the absorbent body 2b of the mask 2. This decreases the degree of precision in shape. In order to solve this problem, the mask 2 should have a trapezoid absorbent body, which is difficult to fabricate. Since the width d of the X-rays is not zero, it is also impossible to form a continuous pattern.
In addition, when the substrate 1 and the mask 2 are retained parallel to each other and X-rays are irradiated vertically to form a pattern 1a of a slanted structure, as shown in FIG. 2, a problem occurs as follows:
If the X-rays are irradiated on the upper surface of the substrate 1, a thickness T of a photosensitive agent, which has been applied on the upper surface of the substrate, is subject to exposure as far as they penetrate into the substrate. Accordingly, this method can form only a pattern 1a of a thickness T of tens or hundreds of μm, which corresponds to the thickness of the substrate. In other words, such a conventional vertical irradiation method cannot continuously form a pattern of a three-dimensional slanted structure having a predetermined thickness or more.